Explanation: I'm glad that you asked this question. When it comes to to biology and the identification of species, domain is the highest rank that you can find in taxonomy. If you look at the taxonomy ranks, this is the order: Domain > Kingdom > Phylum > Class > Order > Family > Genus > Species.
That is why domain includes all of the rest, because in the pyramid, it is the one at the top.
Domain is the taxonomic group that includes kingdoms and all other levels of taxonomy. This is because domain is the highest group that contains all other taxonomy levels. So, just picture it like a pyramid; you have domain at the top and then you have phylum, genus, species, etc
